A typical R-744 transcritical refrigeration system uses a flash-gas bypass between the receiver and the suction inlet of the transcritical compressors. The use of flash-gas bypass is necessary due to the fact that at elevated ambient temperature (around 90° F.) the mass flow of R-744 after the throttling device comprises about 55% liquid and 45% vapors (these values are function of the evaporating temperature). The vapors must be fed back to the compressors suction in order to maintain the compressors mass flow rate. It is clear that only a portion of the compressors mass flow is used to feed the evaporators thus reducing greatly the energy efficiency of the compressors (EER).
The need to improve the cycle efficiency during the warmer periods of the year is obvious.
Accordingly, there is a need for an improved transcritical R-744 refrigeration system.